Measuring the transverse baryonic acoustic scale from the SDSS DR11 galaxies

TL;DR

This paper presents five measurements of the transverse baryonic acoustic scale from SDSS DR11 galaxies, providing a nearly model-independent way to estimate the sound horizon and constrain cosmological parameters.

Contribution

It introduces a method to measure the transverse BAO scale using angular correlation functions in thin redshift shells, offering a CMB-independent approach to cosmology.

Findings

Measured $ heta_{BAO}$ in five redshift shells with high galaxy density.

Provided constraints on dark energy parameters using $ heta_{BAO}$ and CMB data.

Demonstrated a nearly model-independent estimation of the sound horizon.

Abstract

We report five measurements of the transverse baryonic acoustic scale, $\theta_{BAO}$, obtained from the angular two-point correlation function calculation for Luminous Red Galaxies of the eleventh data release of the Sloan Digital Sky Survey (SDSS). Each measurement has been obtained by considering a thin redshift shell ($\delta z = 0.01$ and $0.02$) in the interval $ z \in [0.565, 0.660] $, which contains a large density of galaxies ($\sim 20,000$ galaxies/redshift shell). Differently from the three-dimensional Baryon Acoustic Oscillations (BAO) measurements, these data points are obtained almost model-independently and provide a Cosmic Microwave Background (CMB)-independent way to estimate the sound horizon $ r_s $. Assuming a time-dependent equation-of-state parameter for the dark energy, we also discuss constraints on the main cosmological parameters from $\theta_{BAO}$ and CMB data.